Chimeric design of Pyrrolysyl-tRNA synthetase/tRNA pairs and canonical synthetase/tRNA pairs for genetic code expansion

ABSTRACT: An orthogonal aminoacyl-tRNA synthetase/tRNA pair is a key prerequisite for site-specific incorporation of unnatural amino acids. Due to its high codon suppression efficiency and full orthogonality, the pyrrolysyl-tRNA synthetase/pyrrolysyl-tRNA pair is currently the ideal system for genetic code expansion in both eukaryotes and prokaryotes. There is a pressing need to discover or engineer other fully orthogonal translation systems that allow unnatural amino acids with distinct scaffolds and functionalities to be incorporated into a wide range of living organisms efficiently. Here, through rational chimera design by transplanting the key orthogonal components from the pyrrolysine system, we create multiple chimeric tRNA synthetase/chimeric tRNA pairs, including chimera histidine, phenylalanine, and alanine systems. We further show that these engineered chimeric systems are orthogonal and highly efficient with comparable flexibility to the pyrrolysine system. In addition, the chimera phenylalanine system can incorporate a group of phenylalanine, tyrosine and tryptophan analogues efficiently in both E. coli and mammalian cells. These aromatic amino acids analogous exhibit unique properties and characteristics, including fluorescence, post-translation modification. To our knowledge, most of these molecules have never been shown to be incorporated with fully orthogonal pairs. Therefore, these chimera pairs offer the potential for incorporation of de novo unnatural amino acids into target proteins for a variety of applications.

INSTRUMENT(S): Q Exactive HF

ORGANISM(S): Escherichia Coli

SUBMITTER: Wenlong Ding  

LAB HEAD: Shixian Lin

PROVIDER: PXD018660 | Pride | 2020-05-25

REPOSITORIES: Pride